This invention relates to baking utensils.
The invention relates primarily to baking utensils which are used on a commercial scale in the food preparation industry where baking pans are used over and over again in automatic or semi-automatic production cycles. For example bread is baked in commercial bakeries in pans which are re-usable. Typically, a pan will be used 5 to 10 times per day or perhaps even more. The re-usable baking pans are conventionally formed of steel and have to be sprayed between each baking operation with release agents such as vegetable oils, oil emulsions or the like which enable the baked bread to be separated from the pan.
The repetitive application of such release agents is not only costly but increases hygiene problems. With time, the use of oil-type release agents leads to a build-up of polymerised oil and carbon deposits on the baking surfaces. Besides creating hygiene problems, there is a drop in thermal efficiency because of the build-ups which take place, leading to increased heat requirements and longer baking times.
One solution to the use of release agents in the form of oils has been glazing of the baking pan surfaces with suitable silicone glazes. A small amount of oil is still, however, required. In addition, because of the limited life of the available glazes, recoating is essential from time to time. Organisations which offer a reglazing service will generally be situated away from the majority of bakeries in small towns and so forth, and the pans therefore have to be taken off line for considerable periods of time, at considerable cost.
Baking pans are, in addition, subject to considerable corrosion and wear and tear in use. The pans are usually moved automatically through the baking cycle on conveyor systems which make use of conveyor chains to engage the undersides of the pans. Eventually, the chains score the undersides of the pans and render them unserviceable. Also, the pans are subjected to rough handling in use and this leads eventually to unserviceability as a result of denting and distortion.
Denting and distortion of pans leads inevitably to jamming of the pans on the production line. One possible solution to the problem of pan wear and corrosion is to increase the metal thickness in the pans. This is, however, counter-productive, because thicker pans require greater heating and hence more power, and cause wear and tear to the baking plant.
Conventionally, four or five pans will be held together permanently in a single unit in side-by-side relationship by a strap or frame. Such arrangements are described in U.S. Pat. No. 3,520,438 (Ahrens et al); U.K. patent application No. 2 075 824 A (Ecko Products) and U.S. Pat. No. 3,463,344 (Temple). This means that if a single pan should become unserviceable, whether as a result of build-up or damage, the whole unit has to be taken off line. While treatment is possible to refurbish a pan suffering from undesirable build-up, typically after 1000 or more baking operations, the facilities where this can be done are not always close to hand. The pan units may therefore have to be sent away for long periods for treatment and this leads to production inefficiency. In the worst case, when a single pan has to be scrapped, the whole unit is scrapped. This is obviously very wasteful, since the straps or frames which hold the pans together will usually be somewhat more robust than the pans themselves and would be capable of many more uses were it not for the deficiencies of the pans. Of course, sound pans are also scrapped.
Clearly, the conventional systems are not satisfactory, and it is an object of the invention to provide an alternative system of baking utensils at least some embodiments of the invention being effective at least to reduce the problems outlined above.